The effect of fiber orientation angle in composite materials on moisture absorption and material degradation after hygrothermal ageing

This paper examines the effect of fiber orientation angle of composite material (T300/5208) on the phenomenon of humidity diffusion. Using an analytical method, humidity concentration through the thickness of plates of E-glass/epoxy and carbon/epoxy (T300/5208) composites are calculated. This method also predicts the saturation in humidity and the time to saturation. Analytical formulations have been proposed [G. Verchery, Moisture diffusion in polymer matrix composites with cyclic environmental conditions, Developments in the Sciences and Technology of Composite Materials, in: A.R. Bunsell, J.F. Jamet, A. Massiah (Eds.), Proceeding of the 5th European Conference on Composites Materials (ECCM5), European Association For Composite Materials (EACM), Bordeaux, France (1992) 505; E. Adda-Bedia, W.S. Han, G. Verchery, Moisture diffusion in polymer matrix composites with cyclic environmental conditions, Textile composites in building construction (TCIBC 1992), in: P. Hamelin, G. Verchery (Eds.), Proceeding of the International Symposium Textile Composites in Building Construction, Pluralis, Paris, Part. 2, Lyon, France (1992a) 127; W.S. Han, E. Adda-Bedia, G. Verchery, Diffusion de l’humidité dans une plaque composite soumise à des conditions d’environnement cycliques”, Anales des Composites, Publication éditée par l’AMAC (1992) 29; E. Adda-Bedia, W.S. Han, G. Verchery, Simplified methods for prediction of moisture diffusion in polymer matrix composites with cyclic environmental conditions, International Journal of Polymers and Polymer Composites 6 (4) (1998) 189] to solve Fick’s equation which describes the kinematics of hygroscopic absorption in materials. The diffusivity in composites being a very important parameter, the present model is described in detail. In addition, a study of the effects of environmental conditions and fiber orientation angle on saturation values and ageing degradation of E-glass/epoxy composites exposed to hygrothermal conditions is proposed.